scholarly journals Physiological Differences in Bleaching Response of the Coral Porites astreoides Along the Florida Keys Reef Tract During High-Temperature Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Elizabeth Ann Lenz ◽  
Lucy A. Bartlett ◽  
Anastasios Stathakopoulos ◽  
Ilsa B. Kuffner
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Florida Keys ◽  
High Temperature Stress ◽  
Geologic History ◽  
Reef Management ◽  
Porites Astreoides ◽  
Dry Tortugas ◽  
Bleaching Response ◽  
Reef Tract

The Florida Keys reef tract (FKRT) has a unique geological history wherein Holocene sea-level rise and bathymetry interacted, resulting in a reef-building system with notable spatial differences in reef development. Overprinted on this geologic history, recent global and local stressors have led to degraded reefs dominated by fleshy algae, soft corals, and sponges. Here, we assessed how coral physiology (calcification rate, tissue thickness, reproduction, symbiosis, and bleaching) varies seasonally (winter vs. summer) and geographically using 40 colonies of the mustard hill coral Porites astreoides from four sites across 350 km along the FKRT from 2015 to 2017. The study coincided with a high-temperature event in late summer 2015 that caused heterogeneous levels of coral bleaching across sites. Bleaching severity differed by site, with bleaching response more aligned with heat stress retroactively calculated from local degree heating weeks than those predicted by satellites. Despite differences in temperature profiles and bleaching severity, all colonies hosted Symbiodiniaceae of the same genus (formerly Clade A and subtypes). Overall, P. astreoides at Dry Tortugas National Park, the consistently coolest site, had the highest calcification rates, symbiont cell densities, and reproductive potential (all colonies were reproductive, with most planula larvae per polyp). Corals at Dry Tortugas and Fowey Rocks Light demonstrated strong seasonality in net calcification (higher in summer) and did not express visual or partial-mortality responses from the bleaching event; in contrast, colonies in the middle and southern part of the upper keys, Sombrero Key and Crocker Reef, demonstrated similar reduced fitness from bleaching, but differential recovery trajectories following the heat stress. Identifying reefs, such as Dry Tortugas and possibly Fowey Rocks Light that may serve as heat-stress refugia, is important in selecting candidate sites for adaptive reef-management strategies, such as selective propagation and assisted gene flow, to increase coral-species adaptation to ocean warming.

scholarly journals Wheat (Triticum aestivum L.) TaHMW1D Transcript Variants Are Highly Expressed in Response to Heat Stress and in Grains Located in Distal Part of the Spike

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Two Dimensional Gel Electrophoresis ◽  
Transcript Variants

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.

scholarly journals Genetic structure and diversity of the mustard hill coral Porites astreoides along the Florida Keys reef tract

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Relatedness ◽  
Florida Keys ◽  
Genetic Population ◽  
High Genetic Diversity ◽  
Western Atlantic ◽  
Porites Astreoides ◽  
Single Well ◽  
Reef Tract

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

Emergence of seedlings from different depths following high temperature stress

1975 ◽  
Vol 84 (3) ◽  
pp. 525-528 ◽  
Author(s):  
I. C. Onwueme ◽  
S. A. Adegoroye
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Seedling Emergence ◽  
High Temperature Stress ◽  
Moist Soil ◽  
Different Depths

SUMMARYSeeds of Amaranthus, melon, cowpea and tomato were planted in moist soil at 1, 4 or 7·5 cm depth and subjected to a heat stress of 45 °C for 10 h on the day of sowing (day 0), 1 day after sowing or 2 days after sowing. Seedling emergence was retarded by heat stress, the most drastic retardation being due to heat stress on day 1 for cowpea and tomato, day 2 for melon, and day 0 for Amaranthus. Emergence also decreased with increasing depth of sowing. The interaction of depth and heat stress was also significant in all cases, such that the delay in emergence due to heat stress tended to be greater with increasing depth of sowing. The agronomic significance of the results is discussed.

scholarly journals Differential modulation of heat inducible genes across diverse genotypes and molecular cloning of a sHSP from Pearl millet [Pennisetum glaucum (L.) R. Br.]

2020 ◽  
Author(s):  
S MukeshSankar ◽  
C. Tara Satyavathi ◽  
Sharmistha Barthakur ◽  
S.P Singh ◽  
Roshan Kumar ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Pearl Millet ◽  
Temperature Stress ◽  
Expression Profiling ◽  
Stability Index ◽  
High Temperature Stress ◽  
Seedling Stage ◽  
Transcript Expression ◽  
Membrane Stability Index

AbstractEnvironmental stresses negatively influence survival, biomass and grain yield of most crops. Towards functionally clarifying the role of heat responsive genes in Pearl millet under high temperature stress, the present study were carried out using semi quantitative RT- PCR for transcript expression profiling of hsf and hsps in 8 different inbred lines at seedling stage, which was earlier identified as thermo tolerant/susceptible lines through initial screening for thermo tolerance using membrane stability index among 38 elite genotypes. Transcript expression pattern suggested existence of differential response among different genotypes in response to heat stress in the form of accumulation of heat shock responsive gene transcripts. Genotypes WGI 126, TT-1 and MS 841B responded positively towards high temperature stress for transcript accumulation for both Pgcp 70 and Pghsf and also had better growth under heat stress, whereas PPMI 69 showed the least responsiveness to transcript induction supporting the membrane stability index data for scoring thermotolerance, suggesting the efficacy of transcript expression profiling as a molecular based screening technique for identification of thermotolerant genes and genotypes at particular crop growth stages. As to demonstrate this, a full length cDNA of Pghsp 16.97 was cloned from the thermotolerant cultivar, WGI 126 and characterized for thermotolerance. The results of demonstration set forth the transcript profiling for heat tolerant genes can be a very useful technique for high throughput screening of tolerant genotypes at molecular level from large cultivar collections at seedling stage.

scholarly journals Phenotypic diversity and marker-trait association studies under heat stress in tomato (Solanum lycopersicum L.)

2019 ◽  
Vol 13 ((04) 2019) ◽  
pp. 578-587 ◽  
Author(s):  
Muhammed Alsamir ◽  
Nabil Ahmad ◽  
Vivi Arief ◽  
Tariq Mahmood ◽  
Richard Trethowan
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Phenotypic Diversity ◽  
Association Studies ◽  
High Temperature Stress ◽  
Control Treatment ◽  
Genome Wide Association Studies ◽  
Phenotypic Data ◽  
Tomato Genotypes

Tomato is a mild season crop and high temperature stress impacts productivity negatively. However, the development of cultivars with improved heat tolerance is possible as genetic variability has been consistently reported. This study aimed to identify candidate genes that impact various traits under heat stress. Genome-wide association studies (GWAS) were conducted on a diverse set of 144 tomato genotypes collected from various germplasm centers and breeding programs. The genotypes were grown under control and heat stress in poly tunnels having mean temperatures of 30°C and 45°C for two seasons and phenotypic data were collected on seven agro-physiological traits. All individuals were genotyped withthe80K DArTseq platform using 31237 SNP markers. Data were analysed using a mixed model based on restricted maximum likelihood (REML). Pattern analysis of the phenotypic data showed five primary clusters each with genotypes from multiple origins. Based on the genotypic data, three wild tomato genotypes showed a degree of un-relatedness with the other materials as they were distantly located from the rest of the genotypes in the scatter plot. Control treatment data were used to ascertain markers that are exclusively important under high temperature stress. A large number of markers were significantly associated with various traits under heat stress. These included strong marker associations for number of inflorescence/plant (IPP), number of flowers/inflorescence (FPI), fresh fruit weight (FFrW), and electrolyte leakage (EL). High association with EL was found due to two SNPs 7858523|F|0-25:G>A-25:G>A and 4705224|F|0-60:C>G-60:C>G located on Chr 6. Other less pronounced marker-trait associations were observed for plant dry weight (PDW), and number of fruit/plant (FrPP).

Agronomic, physiological and molecular characterisation of rice mutants revealed the key role of reactive oxygen species and catalase in high-temperature stress tolerance

2020 ◽  
Vol 47 (5) ◽  
pp. 440 ◽  
Author(s):  
Syed Adeel Zafar ◽  
Amjad Hameed ◽  
Muhammad Ashraf ◽  
Abdus Salam Khan ◽  
Zia-ul- Qamar ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
High Temperature Stress ◽  
Oxygen Species ◽  
Selection Indices ◽  
Heat Tolerant

Climatic variations have increased the occurrence of heat stress during critical growth stages, which negatively affects grain yield in rice. Plants adapt to harsh environments, and particularly high-temperature stress, by regulating their physiological and biochemical processes, which are key tolerance mechanisms. The identification of heat-tolerant rice genotypes and reliable selection indices are crucial for rice improvement programs. Here, we evaluated the response of a rice mutant population for high-temperature stress at the seedling and reproductive stages based on agronomic, physiological and molecular indices. Estimates of variance components revealed significant differences (P < 0.001) among genotypes, treatments and their interactions for almost all traits. The principal component analysis showed significant diversity among genotypes and traits under high-temperature stress. The mutant HTT-121 was identified as the most heat-tolerant mutant with higher grain yield, panicle fertility, cell membrane thermo-stability (CMTS) and antioxidant enzyme levels under heat stress. Various seedling-based morpho-physiological traits (leaf fresh weight, relative water contents, malondialdehyde, CMTS) and biochemical traits (superoxide dismutase, catalase and hydrogen peroxide) explained variations in grain yield that could be used as selection indices for heat tolerance in rice during early growth. Notably, heat-sensitive mutants accumulated reactive oxygen species, reduced catalase activity and upregulated OsSRFP1 expression under heat stress, suggesting their key roles in regulating heat tolerance in rice. The heat-tolerant mutants identified in this study could be used in breeding programs and to develop mapping populations to unravel the underlying genetic architecture for heat-stress adaptability.

scholarly journals Effect of high temperature on the reproductive development of chickpea genotypes under controlled environments

2012 ◽  
Vol 39 (12) ◽  
pp. 1009 ◽  
Author(s):  
Viola Devasirvatham ◽  
Pooran M. Gaur ◽  
Nalini Mallikarjuna ◽  
Raju N. Tokachichu ◽  
Richard M. Trethowan ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Pollen Germination ◽  
Pollen Viability ◽  
Pollen Grains ◽  
High Temperature Stress ◽  
Pollen Production ◽  
Seed Number ◽  
Controlled Environments

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.

scholarly journals Effect of Terminal High Temperature Imposed by Late Sowing on Phenological Traits of Wheat

2015 ◽  
Vol 18 (1) ◽  
pp. 13-25
Author(s):  
M Ilias Hossain ◽  
MRI Mondal ◽  
MJ Islam ◽  
MA Hakim ◽  
MK Sultan
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Stress Condition ◽  
High Temperature Stress ◽  
Yield Reduction ◽  
Stressed Condition ◽  
New Varieties ◽  
Heat Stress Condition ◽  
Late Sowing

Phenological performance in relation to yield of wheat genotypes; BARI Gom 26, BAW 1051, BARI Gom 27 and BARI Gom 28 were evaluated under normal and heat stress environments. One irrigated timely sowing (ITS) and three irrigated late sowings (ILS) were imposed to provide terminal high temperature over the tested genotypes. The ITS was November 25 and three ILS were December 10, December 25 and January 10. In heat stress condition, the genotypes phased a significant level of high temperature stress which affected on phenological stage and yield compared to ITS. In ITS situation, days to anthesis and booting decreased in heat stress condition regardless the cultivars. The phenological characteristics under heat stressed condition led the wheat cultivars to significantly lower grain yield as compared to normal condition. In heat stress situations (Dec 10–Jan 10), the average grain yield was reduced by12.8 -39.8 % in BARI Gom 26, 14.4-29.7% in BAW 1051, 11.5-26.5% in BARI Gom 27 and 17.4-25.6 % in BARI Gom 28 in both the season. It was also observed that grain yield was found to be reduced by about 7.7-15.4% in BARI Gom 26, 9.4-15.7 % in BAW 1051, 9.4-12.4% in BARI Gom 27 and 9.7-12.0% in BARI Gom 28 from ITS for each 1°C rise in average mean air temperature during booting to maturity. On the other hand, reduction percent were less for the new varieties. Grain yield reduction was about 1.4 - 2.65% in BARI Gom 28, 0.1-6.7 % in BARI Gom 27 and 1.7-6.0% in BAW 1051.Bangladesh Agron. J. 2015, 18(1): 13-25

Evaluation of heat stress and leaf rust tolerance between very late planted durum and bread wheat cultivars in central India

2007 ◽  
Vol 47 (12) ◽  
pp. 1422 ◽  
Author(s):  
U. K. Behera ◽  
A. N. Mishra ◽  
H. N. Pandey
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Durum Wheat ◽  
Leaf Rust ◽  
Bread Wheat ◽  
Cropping System ◽  
Central India ◽  
High Temperature Stress ◽  
Wheat Cultivars ◽  
Rust Infection

Soybean [Glycine max (L.) Merr.]–wheat (Triticum aestivum L.) is the common cropping system in the Vertisols of central India. High temperatures prevailing during the reproductive phase and leaf rust infection of the late-planted wheat crop affect the grain yield adversely. In the soybean–potato–wheat cropping system, which has recently become more popular, wheat is sown very late, so high temperature stress is a major concern. Understanding of the response of very late-sown durum and bread wheat to high temperature stress during grain filling will assist breeders in genotype improvement and development of best agronomic management practices for promotion of very late-sown wheat cultivation in the region. Information is lacking on the response of durum and bread wheat to leaf rust and heat stress under very late-sown situations. Field experiments were conducted for three consecutive spring (January to April) seasons, from 1996 to 1998, with 20 cultivars of durum (Triticum turgidum L. var. durum Desf.) and bread (Triticum aestivum L. emend. Fiori. and Paol.) wheat of timely and late-sown groups. The study objective was to: (i) identify durum and bread wheat cultivars suitable for very late planting in the newly established soybean–potato–wheat multiple cropping system; (ii) evaluate differential performance of durum and bread wheat under very late-sown conditions; and (iii) characterise plant traits associated with tolerance to heat stress during the grain filling period. Each year, all the cultivars were planted very late in January in lieu of normal sowing in mid-November. Compared with both the timely and late-sown groups of bread wheat cultivars, durum wheat produced an average 6% higher grain yield when sown very late. The 1000-grain weight was the most affected yield attribute under high temperature. Thus, under very late sown conditions, stable and high 1000-grain weight (45–55 g), and high harvest index (41–52%) contributed to the higher yield of durum wheat. Durum cultivar HI 8498 and bread wheat cultivars GW 173, HI 1418 and DL 788-2 of early to medium maturity and with high yields (>4.0 t/ha) and water use efficiency (12.7–14.8 kg/ha.mm) proved promising. Durum cultivars remained free from leaf rust infection, while significant yield reduction was recorded in susceptible bread wheat cultivars, particularly DL 803-3 and GW 190. This was due to severe rust infection during 1997–98, when widespread incidence of leaf rust occurred in the region. Therefore, contrary to the popular belief, late planted durum wheat may be successfully grown in the soybean–potato–wheat cropping system in central India.

scholarly journals Comparative transcriptome analysis reveals gene network regulation of TGase-induced thermotolerance in tomato

2021 ◽  
Vol 49 (1) ◽  
pp. 12208
Author(s):  
Mohammad S. JAHAN ◽  
Zhengrong SHI ◽  
Min ZHONG ◽  
Yuemei ZHANG ◽  
Ranran ZHOU ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Carbon Fixation ◽  
Mrna Level ◽  
High Temperature Stress ◽  
Vital Role ◽  
Protein Processing ◽  
Rna Seq ◽  
Wild Type ◽  
Shed Light

Transglutaminase (TGase), the ubiquitous protein in plants, catalyzes the post-translational transformation of proteins and plays a vital role in photosynthesis. However, its role and mechanism in tomato subjected to heat stress still remain unknown. Here, we carried out a transcriptomic assay to compare the differentially expressed genes (DEGs) between wild type (WT) and TGase overexpression (TGaseOE) plants employed to high-temperature at 42 °C and samples were collected after 0, 6, and 12 h, respectively. A total of 11,516 DEGs were identified from heat-stressed seedlings, while 1,148 and 1,353 DEGs were up-and down-regulated, respectively. The DEGs upon high-temperature stress were closely associated with the pathways encompassing protein processing in the endoplasmic reticulum, carbon fixation, and photosynthetic metabolism. In addition, 425 putative transcription factors (TFs) were identified, and the majority of them associated with the bHLH, HSF, AP2/ERF, MYB, and WRKY families. RNA-seq data validation further confirmed that 8 genes were linked to protein processing and photosynthesis, and the mRNA level of these genes in TGaseOE was higher than that in WT plants, which is consistent in transcriptome results. In conclusion, these results reveal the transcriptional regulation between WT and TGaseOE in tomato under heat stress and shed light on a new dimension of knowledge of TGase-mediated thermotolerance mechanism at the molecular level.

Sign in / Sign up

Export Citation Format

Share Document